1. Field of the Invention
This invention relates generally to motor vehicle trim and more particularly to wheel cover retention systems.
2. Background History
Traditionally, utility vehicle wheels were mounted to wheel hubs by lugs and lug nuts which remained exposed. In automotive applications, however, an early practice was to cover the wheel hub and lug nuts with a hub cap mounted to a central dish area of the wheel. The hub cap covered and protected the lug nuts and wheel bearings from the corrosive effects of moisture, sand, dirt and road chemicals. The advent of wheel covers, which served to conceal the outer face of a wheel up to the wheel rim, presented challenges with respect to providing secure mounting systems.
Some suggested mounting arrangements appreciated the fact that the wheel lug nuts could be utilized to hold the wheel cover against the wheel. In United Kingdom patent document no. 1,327,391 a wheel cover included selected openings registered with the wheel lug nuts which were of a size greater than the lug nuts and selected openings of a smaller size which permitted the wheel cover to slip over the lugs only. The lug nuts registered with the smaller sized openings were removed, the wheel cover then positioned against the wheel and the lug nuts were replaced to fasten the cover.
Among the disadvantages encountered with such system was the fact that at least some lug nuts were required to be removed in order to mount or dismount the wheel cover. Further, the wheel lug nuts were exposed to the corrosive effects of the road environment. Additionally, exposed conventional steel lug nuts presented an unsightly appearance in contrast to polished wheel covers.
Irrespective of attempts to utilize lug nuts for securing wheel covers, the general employment of exposed wheel lug nuts in passenger vehicle applications has increased in recent years. Among contributing factors have been the increased popularity of aftermarket chromed or cast metal dress wheels and the prevalence of OEM option and standard equipment cast wheels. Such applications necessitated the use of chromed wheel lug nuts which significantly increased costs as compared to conventional lug nuts.
While some cost savings have been achieved through the use of chromed metal lug nut covers as illustrated in copending U.S. Pat. application Ser. No. 07/483,748 filed Feb. 22, 1990 and assigned by the assignee of the present invention, chromed metal lug nut covers were themselves quite costly, e.g. several times the cost of the conventional lug nuts which they protected. Further, chromed metal covers could be dislodged with relative ease.